• Korean Journal of Cognitive Science
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• v.11 no.3_4
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• pp.57-72
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• 2000

A Korean standardized set of pictures has been called for as more and more studies utilized picture stimuli among memory and representation research. This article presents a Korean standardized set of pictures for studies probing the cognitive mechanisms that underlie picture and word processing or studies that simply utilize pictures stimuli. This norm provides 213 pictures, data on several variables such as name agreement, appropriateness of pictures. and familiarity. Previous data on such variables as frequency. category. and frequency within a category have been integrated 1 into this norm. Limitation, usage. and application of this set are discussed in terms of 1 implicit and explicit memory, and those variables mentioned previously.

• Journal of Korean Society of Forest Science
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• v.97 no.4
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• pp.423-430
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• 2008

Negative ion is considered as one of the forest health attributes. The overall purpose of this study was to investigate the influence of air negative ions on physiological effects. Data were collected from 12 volunteers (university students) who were randomly assigned into treatment and control groups. Subjects in treatment group were exposed to air with negative (2,001,000 ion/cc). Using pretest-posttest control group design, blood cortisol, norepinephrine, epinephrine, and cognitive function were measured. Data analysis indicated that negative ions influenced on positive effects of stress responses.

• Journal of Korean Library and Information Science Society
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• v.41 no.4
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• pp.383-402
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• 2010

This study was conducted to investigate the effectiveness of bibliotherapy on the levels of cognitive function, depression, and social behavior in the elderly with mild dementia. For this quasi-experimental research, a total of 166 subjects the age of from 90 to 65 were selected of the 166, were divided into the experimental group and control group for six months. These findings confirmed that the dementia Bibliotherapy program made a contribution to improve cognitive function and social behavior, and to reduce depression in the elderly with mild dementia. Therefore, it is recommended that this program be used in clinical practice as an effective Bibliotherapy program for the elderly with mild dementia.

• Journal of the Korean Society for Library and Information Science
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• v.33 no.1
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• pp.49-65
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• 1999

The purpose of this study was to examine the impacts of individual factors, such as demographic characteristics, personality types and cognitive styles, on job satisfaction of university librarians. The study further investigated the relationships and interaction effects among those factors. Three independent variables examined were demographic characteristics (sex, age, year at work, and position), personality types (Type A and Type B), and cognitive styles (Held-dependence and Held-independence). The dependent varilable was the level of job satisfaction. five factors that affect the level of job satisfaction were the nature of work, salary level promotion practices, supervision style, and the relationships with co-wokers. The number of subjects participated in the study was 166 university librarians working in Pusan area. The SPSSWIN package was used for statistical analysis.

• Journal of Korean Physical Therapy Science
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• v.19 no.4
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• pp.27-34
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• 2012

The aim of study was to assess the effectiveness of dementia elderly persons on the cognitive function, Activities of Daily Living(ADL) and balance-performing ability the group therapeutic exercise programs. Fifteen community-dwelling subjects participated in this study. An 4-week group therapeutic exercise program, including strengthening and balance training, breathing and gait exercise, and recreation, consisted of activities related to daily living. The Mini-Mental State Examination-korean(MMSE-K), Modified Barthel Index(MBI), Berg Balance Scale(BBS), and Timed Up & Go (TUG) test were measured during before and after exercise points The results of this study were as follows : 1) After eight weeks, the MMSE-K and MBI total scores were significantly increased to more after than before(p<.05, p<.01). 2) in the MBI contents, personal hygiene, dressing, ambulation and chair, bed transfers scores were significant increased to after. 3) after BBS, TUG scores were statistically significant higher than the before scores(p<.05, p<.05, p<.01). These findings suggest that group therapeutic exercise program can be used to improve the cognitive function, ADL and balance-performing ability in dementia elderly persons.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.5
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• pp.1514-1531
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• 2014

Femtocell provides better coverage and higher spectrum efficiency in areas rarely covered by macrocells. However, serious two-tier interference emerging from randomly deploying femtocells may create dead zones where the service is unavailable for macro-users. In this paper, we present adopting cognitive radio spectrum overlay to avoid intra-tier interference and incorporating spectrum underlay and overlay to coordinate cross-tier interference. It is a novel centralized control strategy appropriate for both uplink and downlink transmission. We introduce the application of proper spectrum sharing strategy plus optimal power allocation to address the issue of OFDM-based femtocells interference-limited downlink transmission, along with, a low-complexity suboptimal solution proposed. Simulation results illustrate the proposed optimal scheme achieves the highest transmission rate on successfully avoiding two-tier interference, and outperforms the traditional spectrum underlay or spectrum overlay, via maximizing the opportunity to transmit. Moreover, the strength of our proposed schemes is further demonstrated by comparison with previous classic power allocation methods, in terms of transmission rate, computational complexity and signal peak-to-average power ratio.

• Journal of the Korean Society of Food Culture
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• v.32 no.2
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• pp.89-98
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• 2017

To enrich a country's food culture, it is essential that residents understand and care about that culture. Although various efforts to globalize Korean food have been made outside Korea, the importance of understanding Koreans' perception of and increasing interest in Korean food has been neglected. Thus, this study was conducted to identify the cognitive structures regarding Korean food among 30 Koreans living in metropolitan cities using in-depth laddering interviews based on the means-end chain theory. The most dominant cognitive structures toward Korean food were familiarity (attributes), ease of digestion and health (functional consequences), sense of responsibility and will to live (psychosocial consequences), and family affection and sense of achievement (values). In short, Koreans were found to consume Korean food to achieve perceived high-dimensional values rather than simply for its attributes or benefits. These findings have important implications for future strategies and policies aimed at increasing Korean food consumption by Koreans, as they suggest that underlying and symbolic values rather than the attributes of Korean food are more effective in promoting its consumption. Further studies on understanding perceptions and values using a larger Korean population are needed to preserve and further develop Korean food.

• Journal of Communications and Networks
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• v.16 no.2
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• pp.193-201
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• 2014

In cognitive radio networks, the packet transmissions of the secondary users (SUs) can be interrupted randomly by the primary users (PUs). That is to say, the PU packets have preemptive priority over the SU packets. In order to enhance the quality of service (QoS) for the SUs, we propose a spectrum access strategy with an ${\alpha}$-Retry policy. A buffer is deployed for the SU packets. An interrupted SU packet will return to the buffer with probability ${\alpha}$ for later retrial, or leave the system with probability (1-${\alpha}$). For mathematical analysis, we build a preemptive priority queue and model the spectrum access strategy with an ${\alpha}$-Retry policy as a two-dimensional discrete-time Markov chain (DTMC).We give the transition probability matrix of the Markov chain and obtain the steady-state distribution. Accordingly, we derive the formulas for the blocked rate, the forced dropping rate, the throughput and the average delay of the SU packets. With numerical results, we show the influence of the retrial probability for the strategy proposed in this paper on different performance measures. Finally, based on the trade-off between different performance measures, we construct a cost function and optimize the retrial probabilities with respect to different system parameters by employing an iterative algorithm.

• Journal of electromagnetic engineering and science
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• v.16 no.1
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• pp.19-23
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• 2016

This paper presents a novel design for dual-band bandpass filters. The proposed filters are applicable to the carrier aggregation of the TV white space (TVWS) band and long-term evolution (LTE) band for cognitive radio applications. The lower passband is the TVWS band (470-698 MHz) whose fractional bandwidth is 40 %, while the higher passband is the LTE band (824-894 MHz) with 8 % fractional bandwidth. Since the two passbands are located very close to each other, a transmission zero is inserted to enhance the rejection level between the two passbands. The TVWS band filter is designed using magnetic coupling to obtain a wide bandwidth, and the LTE band filter is designed using dielectric resonators to achieve good insertion loss characteristics. In addition, in the proposed design, a transmission zero is placed with cross-coupling. The proposed dual-band bandpass filter is designed as a two-port filter (one input/one output) as well as a three-port filter (one common input/two outputs). The measured performances show good agreement with the simulated performances.

• Journal of electromagnetic engineering and science
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• v.11 no.2
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• pp.128-132
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• 2011

In interference tolerance based spectrum sharing systems, primary receivers (PRs) are protected by a predefined peak or average interference power constraint. To implement such systems, cognitive radio (CR) transmitters are required to adjust their transmit power so that the interference power received at the PR receivers is kept below the threshold value. Hence, a CR-transmitter requires knowledge of its channel and the primary receiver in order to allocate the transmit power. In practice, it is impossible or very difficult for a CR transmitter to have perfect knowledge of this channel state information (CSI). In this paper, we investigate the impact of imperfect knowledge of this CSI on the performances of both a primary and cognitive radio network. For fixed transmit power, average interference power (AIP) constraint can be maintained through knowledge of the channel distribution information. To maintain the peak interference power (PIP) constraint, on the other hand, the CR-transmitter requires the instantaneous CSI of its channel with the primary receiver. First, we show that, compared to the PIP constraint with perfect CSI, the AIP constraint is advantageous for primary users but not for CR users. Then, we consider a PIP constraint with imperfect CSI at the CR-transmitter. We show that inaccuracy in CSI reduces the interference at the PR-receivers that is caused by the CR-transmitter. Consequently the proposed schemes improve the capacity of the primary links. Contrarily, the capacities of the CR links significantly degrade due to the inaccuracy in CSI.